50/1 vs 25/1

I run all my saws on 50/1 as instructed but my dad swears by 25/1 and claims they 'won't run properly' on anything else. Is he going to screw up his saws / strimmers this way? they do smoke a bit when he uses them and don't sound right to me. Silly old b*$%r that he is.

I made the mistake of lending my 345e to a 'tree surgeon' the other day as he needed an 18" bar to fell and awkward Ash I didn't fell confident enough to tackle. I caught him mixing the fuel in the saw (bit of petrol, capful of oil etc. ). It seems OK but I binned his evil mix and re-filled with the right stuff ASAP.

Am I being silly about this? Trashing a £300 saw seems a but silly to me just out of laziness / idiocy.

If you use good quality 2 stroke then 50-1.....and TBH you should ONLY use good quality 2 stroke. I, and probably most Arbtalkers, use the likes of Stihl or Husky branded stuff or equivalently priced stuff. If you run it at 25-1 you wont really do any damage as such, and if you are using cheapo 2 stroke then you would be advised to.

IMO any tree surgeon worth his salt wouldnt dream of mixing the oil and fuel in the saw, but would mix it 5 litres at a time in a proper can:sneaky2:

HI MATE its STIHL 2 st oil here all the best jon

I use Stihl Ultra at 50:1 (ish), I tend to add a bit more oil so it's slightly over the 50 line on the bottle. I only use my own fuel, if I'm working for someone else I will still take my own can and use that rather than fuel which I don't know the age of, or if it's been mixed properly... not worth the risk IMO

Noone should be mixing fuel in the saw, and they would not be using my kit again if that happened to me!

50/1 unless the manufacturer states otherwise,and always a good quality oil.

Mixing in the tank is ridiculous.

Good quality 50:1 mixed directly at the filling station in 5, 10 or 20 Ltrs at a time to make it easy on the maths and no confusion over "is this mixed or does it need oil ?"

This article might be of interest to some - it's out of Washington (State) and has some relevant info. Madsen's have an interesting web site.

Pro Saw Maintenance & Repair Menu

Hope the link works if not just Google Madsen's

I only use Stihl oil and have a gallon can marked up at 50:1 with a marker which gets mixed when filled from a bigger jerry. I still use the pot which came free with my 345e as one of those full in a gallon is 50:1. I can't get on with those fancy bottles they give you which are supposed to measure it out. A bit too krypton factor for my cider addled brain. I've heard that motorbike oil can do serious damage to a saw engine.

Interesting article from Madsens, thanks for that.

In the 70s/80s, the two stroke oil was not as good as it is now, in those days a 25:1 mix would have been the done thing, with modern oils they specify 50:1 but personally use 40:1 to ensure that an air leak or weak mixture at the top end will not mess the engine up too much.

That piston on the Madisen link looks like heat seizure to me - I would have thought detonation would have damaged the crown of the piston - I have around 15 pistons from refurbed saws that look like that!